CA1096570A - Integral, electrically-conductive textile filament - Google Patents
Integral, electrically-conductive textile filamentInfo
- Publication number
- CA1096570A CA1096570A CA277,204A CA277204A CA1096570A CA 1096570 A CA1096570 A CA 1096570A CA 277204 A CA277204 A CA 277204A CA 1096570 A CA1096570 A CA 1096570A
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- CA
- Canada
- Prior art keywords
- electrically
- filament
- percent
- weight
- integral
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- D—TEXTILES; PAPER
- D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
- D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
- D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
- D02G3/44—Yarns or threads characterised by the purpose for which they are designed
- D02G3/441—Yarns or threads with antistatic, conductive or radiation-shielding properties
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F1/00—General methods for the manufacture of artificial filaments or the like
- D01F1/02—Addition of substances to the spinning solution or to the melt
- D01F1/09—Addition of substances to the spinning solution or to the melt for making electroconductive or anti-static filaments
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F8/00—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof
- D01F8/04—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers
- D01F8/08—Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof from synthetic polymers with at least one polyacrylonitrile as constituent
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Artificial Filaments (AREA)
- Multicomponent Fibers (AREA)
- Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
The invention is an integral, electrically-conductive textile filament comprising from 2 to about 1000 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material, and one non-conducting stratum of the same polymeric material in coextensive union with each electrically-conducting stratum along the length of at least one of its major surfaces. Each electrically-conducting stratum of polymeric material has dispersed therein finely-divided particles of electrically-conductive carbon block. The electrical resistance of the integral filament is not more than about 109 ohms/cm.
The invention is an integral, electrically-conductive textile filament comprising from 2 to about 1000 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material, and one non-conducting stratum of the same polymeric material in coextensive union with each electrically-conducting stratum along the length of at least one of its major surfaces. Each electrically-conducting stratum of polymeric material has dispersed therein finely-divided particles of electrically-conductive carbon block. The electrical resistance of the integral filament is not more than about 109 ohms/cm.
Description
~LQ~
INTEGRAh, ELECTRICALLY-CONDUCTIVE ~EXTI~E FI~.~E~
This invention relates to textiles in general, and in particular to an electrically-conductive textile flber or use in the construction of antistatic fabrics of varlous kinds.
The accumulation of static electricity as a result of the utilization of ~abrics is a phenomenon which has commanded the atten~ion of the textile industry for some time. The presence of static is a cause not only of annoy-ance -- (e.g. items of apparel cling to the body znd are attracted to other garments; fine particles of lint and dust are attractQd to upholstery fabrics, increasing the frequency of required clea~ing; one experiences a jolt or shoc~ upon touching a m~tal doorknob af~er wal~ing across a carpet) -- but also of danger (eag. the discharge of static elec~ricity can resul~ in spar~s capable or igniting 1am-mable mixtures such as ether/air, which are commonlv four.d in nospitals, especially in operating rooms). All of the-ce effects are accentuated in atmospheres of low relative humidi~y.
Of the many proposals for preven~ing the undesir-able uildup of static electricity, the most satis~actory, with r_~pect to their efficiency and permanencP, have appea~ed to be those w~ich comprehend the utilization of fibers ~os-sessing electxical conductivlty ~e.g. metal fibers; fi~ers coated with ~lect_ically-conductive materlal; ibe~s contalnln~
~;
a657~
conductive, block copolymeric materials dispersed therein in the form of long, slender particles; integral fibers having a sheath or core containing electrically-conductive material;
and metallic laminate filaments) in combination with common natural or man-made fibers to produce a woven, knitted, netted, tufted, or otherwise fabricated structure, which readily dissipates the static charges as they are generated.
Some of the more noteworthy of these methods and structures may be found in U. S. patents 2,129,594; 2,714,569; 3,069,746;
3,288,175; 3,329,557; 3,582,444; 3,582,445; 3,582,448;
3,586,597; 3,590,570; 3,637,908; 3,639,502; 3,729,449; 3,803,453 and 3,823,035; in Webber, "Metal Fibers," Modern Textile Magazine, May, 1966, pp. 72-75; in Belgian patents 775,935 and 790,254; and in French patent 2,116,106.
Notwithstanding the efficacy of these and similar expedients, they are found lacking in certain important aspects, viz:
The manufacture of metallic ~ibers of fine denier, especially in the form of monofilaments, is a difficult ànd costly operatiGn; and since such fibers are quite dissimilar in character from ordinary textile fibers, problems arise in connection with blending and processing, as well as in the hand of the products obtained.
Metallic laminate filaments, on the other hand, do not present blending and processing problems, because of their close similarity to ordinary textile fibers, and the hand of the products obtained is consequently not objectionable.
However, the cost of such filaments is high when compared with the natural or man-made fibers with which they are blended.
Textile fiber substrates,the surfaces of which have been coated by vapor deposition or electrodeposition, or by the application of adhesive compositions containing inely di~ided particles of electrically-conductive material, are ~Q~S~7~
in some cases less costly than metal fibers and/or metallic laminate filaments, depending upon the nature of the elec-- trically-conductive material employed and the coating method chosen. However, such coatings are ofter found lacking in cohesion and adhesion and are frequently too thick to be practicable in some applications -- especially when the nature of the electrically-conductive particulate matter is such that a high concentration thereof is required for satis-factory conductivity. Economy is generally achieved, there-fore, only through sacrifices in durability of the conductivity of the fiber.
The extrusion of powdered synthetic polymer/finely divided electrically-conductive material blends directly into filaments, or as distinct coatings on filamentary sub-strates having the same or different polymeric compositions, is also well known. ~nfortunately, these substantially homogeneous blends require a high concentration of the elec-trically-condustive material. They are generally not readily extruded, if at all, and any filaments and filamentary coat-ings which are produced therefrom have extremely poor cohesion and adhesion, and are therefore completely lacking in durability.
Filamentary polymer structures containing conductive polymeric materials (e.g. polyalkylene ether - polyamide block copolymers), which are dispersed in the polymer substrate in the form of long, slender particles or layers whose longitudinal axes are substantially parallel to the direction of molecular orientation of the filament, are difficultly ob-tained in a reproducible form, thereby increasing their cost and/or decreasing the ambit of their utility.
Al~hough they have been shown to provide ver~ bene-ficial results in most applications, filamentary polymeric structures having either an integral sheath or an integral core comprising electrically-conductive material are somewhat limited in their utility; viz., they are not suitable in applications requiring a very low resistance.
Although multi-component filaments are known in the art (see U. ~. patent No. 3,531,368, which discloses a multi-component filament comprising a plurality of fine filamentary parts which are continuous along the axis of the filament), and although it is also old to modify one of the components of a multi-component filamentary structure by the introduction of additives such as anti-static agents, including electrica~ly-conductive carbon black (see U. S.
patents 2,428,046 and 3,582,448), the present invention as hereinbelow specified and hereinafter defined is not obvious to one bf skill in the art, as only the particular combi-nation of elements as recited herein will result in a filament having properties which obviat~ the deficiencies of the prior art as discussed hereinabove.
Accordingly, it is the primary object of this invention to provide a low-cost, yet durable, electrically-conductive iber which has reproducible conductive properties over a wide range o~ conductiYities, substantially retains the desirable physical properties of the unmodi~ied:polymeric substrate, and presents no problems in the blending and pro-cessing thereof with ordinary natural and man~made textile fibers.
SU~ARY OF_THE INVENTION
This object -is achieved, and the disadvantages of the prior art are obviated, by providing an integral electrically-conductive textile filament which has a resistance o~ not more than about 109 ohms/cm and comprises:
14;~aJ~
(a) from 2 to about lOG0 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material having finely-divided particles of electrically-conductive carbon black uniformly dispersed therein, the con-centration of electrically-conductive carbon black in each electrically-conducting stratum being within the following limits:
(1) For 2 electrically-conducting strata:
from about 30 percent by weight -- at a total concentration of carbon in the integral filament of about 1/2 percent by weight -- to ahout 70 percent by weight -- at a total concen-tration of carbon in the integral filament of about 1/4 percent by weight; and
INTEGRAh, ELECTRICALLY-CONDUCTIVE ~EXTI~E FI~.~E~
This invention relates to textiles in general, and in particular to an electrically-conductive textile flber or use in the construction of antistatic fabrics of varlous kinds.
The accumulation of static electricity as a result of the utilization of ~abrics is a phenomenon which has commanded the atten~ion of the textile industry for some time. The presence of static is a cause not only of annoy-ance -- (e.g. items of apparel cling to the body znd are attracted to other garments; fine particles of lint and dust are attractQd to upholstery fabrics, increasing the frequency of required clea~ing; one experiences a jolt or shoc~ upon touching a m~tal doorknob af~er wal~ing across a carpet) -- but also of danger (eag. the discharge of static elec~ricity can resul~ in spar~s capable or igniting 1am-mable mixtures such as ether/air, which are commonlv four.d in nospitals, especially in operating rooms). All of the-ce effects are accentuated in atmospheres of low relative humidi~y.
Of the many proposals for preven~ing the undesir-able uildup of static electricity, the most satis~actory, with r_~pect to their efficiency and permanencP, have appea~ed to be those w~ich comprehend the utilization of fibers ~os-sessing electxical conductivlty ~e.g. metal fibers; fi~ers coated with ~lect_ically-conductive materlal; ibe~s contalnln~
~;
a657~
conductive, block copolymeric materials dispersed therein in the form of long, slender particles; integral fibers having a sheath or core containing electrically-conductive material;
and metallic laminate filaments) in combination with common natural or man-made fibers to produce a woven, knitted, netted, tufted, or otherwise fabricated structure, which readily dissipates the static charges as they are generated.
Some of the more noteworthy of these methods and structures may be found in U. S. patents 2,129,594; 2,714,569; 3,069,746;
3,288,175; 3,329,557; 3,582,444; 3,582,445; 3,582,448;
3,586,597; 3,590,570; 3,637,908; 3,639,502; 3,729,449; 3,803,453 and 3,823,035; in Webber, "Metal Fibers," Modern Textile Magazine, May, 1966, pp. 72-75; in Belgian patents 775,935 and 790,254; and in French patent 2,116,106.
Notwithstanding the efficacy of these and similar expedients, they are found lacking in certain important aspects, viz:
The manufacture of metallic ~ibers of fine denier, especially in the form of monofilaments, is a difficult ànd costly operatiGn; and since such fibers are quite dissimilar in character from ordinary textile fibers, problems arise in connection with blending and processing, as well as in the hand of the products obtained.
Metallic laminate filaments, on the other hand, do not present blending and processing problems, because of their close similarity to ordinary textile fibers, and the hand of the products obtained is consequently not objectionable.
However, the cost of such filaments is high when compared with the natural or man-made fibers with which they are blended.
Textile fiber substrates,the surfaces of which have been coated by vapor deposition or electrodeposition, or by the application of adhesive compositions containing inely di~ided particles of electrically-conductive material, are ~Q~S~7~
in some cases less costly than metal fibers and/or metallic laminate filaments, depending upon the nature of the elec-- trically-conductive material employed and the coating method chosen. However, such coatings are ofter found lacking in cohesion and adhesion and are frequently too thick to be practicable in some applications -- especially when the nature of the electrically-conductive particulate matter is such that a high concentration thereof is required for satis-factory conductivity. Economy is generally achieved, there-fore, only through sacrifices in durability of the conductivity of the fiber.
The extrusion of powdered synthetic polymer/finely divided electrically-conductive material blends directly into filaments, or as distinct coatings on filamentary sub-strates having the same or different polymeric compositions, is also well known. ~nfortunately, these substantially homogeneous blends require a high concentration of the elec-trically-condustive material. They are generally not readily extruded, if at all, and any filaments and filamentary coat-ings which are produced therefrom have extremely poor cohesion and adhesion, and are therefore completely lacking in durability.
Filamentary polymer structures containing conductive polymeric materials (e.g. polyalkylene ether - polyamide block copolymers), which are dispersed in the polymer substrate in the form of long, slender particles or layers whose longitudinal axes are substantially parallel to the direction of molecular orientation of the filament, are difficultly ob-tained in a reproducible form, thereby increasing their cost and/or decreasing the ambit of their utility.
Al~hough they have been shown to provide ver~ bene-ficial results in most applications, filamentary polymeric structures having either an integral sheath or an integral core comprising electrically-conductive material are somewhat limited in their utility; viz., they are not suitable in applications requiring a very low resistance.
Although multi-component filaments are known in the art (see U. ~. patent No. 3,531,368, which discloses a multi-component filament comprising a plurality of fine filamentary parts which are continuous along the axis of the filament), and although it is also old to modify one of the components of a multi-component filamentary structure by the introduction of additives such as anti-static agents, including electrica~ly-conductive carbon black (see U. S.
patents 2,428,046 and 3,582,448), the present invention as hereinbelow specified and hereinafter defined is not obvious to one bf skill in the art, as only the particular combi-nation of elements as recited herein will result in a filament having properties which obviat~ the deficiencies of the prior art as discussed hereinabove.
Accordingly, it is the primary object of this invention to provide a low-cost, yet durable, electrically-conductive iber which has reproducible conductive properties over a wide range o~ conductiYities, substantially retains the desirable physical properties of the unmodi~ied:polymeric substrate, and presents no problems in the blending and pro-cessing thereof with ordinary natural and man~made textile fibers.
SU~ARY OF_THE INVENTION
This object -is achieved, and the disadvantages of the prior art are obviated, by providing an integral electrically-conductive textile filament which has a resistance o~ not more than about 109 ohms/cm and comprises:
14;~aJ~
(a) from 2 to about lOG0 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material having finely-divided particles of electrically-conductive carbon black uniformly dispersed therein, the con-centration of electrically-conductive carbon black in each electrically-conducting stratum being within the following limits:
(1) For 2 electrically-conducting strata:
from about 30 percent by weight -- at a total concentration of carbon in the integral filament of about 1/2 percent by weight -- to ahout 70 percent by weight -- at a total concen-tration of carbon in the integral filament of about 1/4 percent by weight; and
(2) For about 1000 electrically-conducting strata: from about 30 percent by weight -- at a total concen-tration of carbon in the integral filament of about 12 percent by weight -- to about 70 percent by weight -- at a total concentration of carbon in the integral filament of about 2 percent by weight; and (b) in coe~tensive union with each electrically-conducting stratum along the length of at least one major surface thereof, a non-conducting stratum of the same fiber-forming poly~eric material.
Moreover, it is especially advantageous if the polymeric material is an acrylonitrile polymer having at least about 85 percent by weight of acrylonitrile and up to about 15 percent by weight of another polymerizable mono-olefinic monomer copolymerizable therewith.
Furthermore, the integral, electrically-conductive textile filament of the present invention is particularly useful when there are 4 electrically-conducting, longitudinally-directed s~rata o fiber-formin~ po~ymeric material, each having ~inely-divided particles of alectrically-conductive carbon black uniformly dispersed therein in a concentration of 40 - 60 percent by weight, the total concentration of carbon in the inteyral filament being between 4 and 6 percent by weiaht.
7~
The production ~f integral, electrically-conductive filaments according to the present invention is advantageousl~
accomplished by:
(1) providing a first stream of a solution of a fiber-forming polymeric material;
(2) providing a second stream of the same solution of the polymeric material, and dispersing in the second stream the appropriate concentration of a ~inely-divided, electrically-conductive carbon black, which does not dissolve in, or react with the solvent;
Moreover, it is especially advantageous if the polymeric material is an acrylonitrile polymer having at least about 85 percent by weight of acrylonitrile and up to about 15 percent by weight of another polymerizable mono-olefinic monomer copolymerizable therewith.
Furthermore, the integral, electrically-conductive textile filament of the present invention is particularly useful when there are 4 electrically-conducting, longitudinally-directed s~rata o fiber-formin~ po~ymeric material, each having ~inely-divided particles of alectrically-conductive carbon black uniformly dispersed therein in a concentration of 40 - 60 percent by weight, the total concentration of carbon in the inteyral filament being between 4 and 6 percent by weiaht.
7~
The production ~f integral, electrically-conductive filaments according to the present invention is advantageousl~
accomplished by:
(1) providing a first stream of a solution of a fiber-forming polymeric material;
(2) providing a second stream of the same solution of the polymeric material, and dispersing in the second stream the appropriate concentration of a ~inely-divided, electrically-conductive carbon black, which does not dissolve in, or react with the solvent;
(3) providing a third stream identical to the first stream;
(~) providing a fourth stream identical to the second stream; and (5) causing the first, second, third, and fourth streams to join in order into a composite stream without appreciable mixing of the individual component streams thereof, and spinning the resulting composite stream into integral filaments.
In a preferred embodiment of this process, the : first and second streams described above are introduced simul-taneously into the inlet end of an interfacial surface generator which generates between 8 and about 2000 total layers and the resulting multi-layered composite stream is spun into integral filaments by standard wet or dry spinning techniques.
In another preferred embodiment of this process, many filaments are extruded in a tow, which is cut into staple and subsequently handled by conventional methods to produce a conductive spun yarn.
BRIEF DESCRIPTION OF THE DRAWTNG
.
For a more complete understanding of the present invention, reference should be made to the detailed description 57~
of the preferred embodiments thereof, which is set fGrth below, which description should be read together with the accompanying drawing, wherein:
FIG. 1 and FIG. 2 are perspective views schematically illustrating embodiments of an inteyral, electrically-con-ductive filament according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polymeric material comprising the integral, electrically-conductive textile filament of the present invention may be any of the well-known film or fiber-forming polymers commonly employed in the art, such as acrylics, acetates, modacrylics, cellulosics, polystyrenes, polyolefins, polyesters, and polyamides. Acrylonitrile polymers having at least about 85 percent by weight of acrylonitrile and up to about 15 percent by weight of another polymerizable mono-olefinic monomer copolymerizable therewith have been shown to be especially advantageous. The unitary filament must comprise at least two electrically-conducting, longitudinally-directed strata of ~iber-forming polymeric material, each of which has uniformly dispersed therein finely-divided particles of an electrically-conductive carbon black. A particle size of about 20 to 40 m~ is preferred.
The number of electrically-conductive strata and the appropriate concentration of electrically-conductive carbon black in the individual electrically-conductive strata were determined empirically. In this regard, it was desired that the electrical resistance of the unitary filament be not more than about 109 ohms/cm, and for many applications, between about 10- and 109 ohmsjcm. Under the latter conditions, the unitary filament is eminently suitable for employment in a wide variety of fabrics for preventing the accumulation of hiyh charges of static electricity while presenting no appreciable electrocution hazard.
7~
The filament of the present invention accordingly has:
(a) from 2 to about 1000 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material having finely-divided particles of electrically-conductive carbon black uniformly dispersed therein, the concentration of electrically-conductive carbon black in each electrically-conducting stratum being within the following limits:
: 10 (1) For 2 electrically-conducting strata:
: from about 30 percent by weight -- at a total concentration of carbon in the integral filament of about 1/2 percent by weight -- to about 70 percent by weight -- at a total concentra-tion of carbon in the integral filament of about 1/4 percent by weight; and (2) For about 1000 electrically-conducting strata: from about 30 percent by weight -- at a total : concentration of carbon in the integral filament of about ; 12 percent ~y weight -- to about 70 percent by weight --at a total concentration of carbon in the integral filament of about 2 percent by weight; and '~ (b) in coextensive union with each electrically-~ conducting stratum along the length of at least one major : surface therof, a non-conducting stratum of the same ~ 25 fiber-forming pol~meric material.
: Furthermore, the integral, electrically-conductive : textile filament of the present invention is particularly useful when there are 4 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material, each having finely-di~ided particles of electrically-conductive carbon black uniformly dispersed therein in a concentration of ~0 - 60 percent by weight, the total concentration of carbon in the integral filament being between 4 and 6 percPnt by wei~ht.
7(~
Referring to ~he drawing, although t~lo longitudinally-directed electrically-conducting strata (12) are sufficient to afford the combination of properties long sought after (see FIG. 1), a larger number of electrically-conducting strata (12) has been found particularly advantageous. (See FIG. 2, wherein the preferred embodiment comprising 4 electrically-conducting strata (12) is shown.) Each electrically-conducting stratum (12) is joined in a coextensive union along the length of at least one of its major surfaces with a non-conducting stratum (13) of the same polymeric material to form an integral or unitary filamentary structure ~11). As the component strata of this structure cannot be individually separated or removed from the unit, the integral structure (11) of the present invention is decidedly different from those composite structures of the prior art which, comprising distinct layers or plies joined by adhesive and/or the application of heat and pressure, are subject to delamination and/or des~uamation, which in turn results in loss of conductivity of the structure.
Moreover, the electrically-conducting strata (12) of the unitary structure (11) of the present invention are manifestly unlike the prior art's long, slender particles of dispersed conductive block copolymeric material, which are difficultly fashioned in reproducible form from a narrow choice of conductive polymeric materials. In contradist~nction to these prior art structures, the electrically-conducting strata (12) of the unitary filament (11) of the present invention comprise finely divided particles of electrically-conductive carbon black -- e.g., roughly spherical particles of electrically-conductive carbon black having an average diameter of between about 20 and 40 m~ -- uniformly dispersed in a non-conducting polymeric matrix. Moreover, the desired electrical co~ductivity of a variety of polymeric filaments is readily and economically achieved, and easily reproduced.
;5~
The height of each electrically-conducting stratum (12) is not critical. It varies with the diameter of the filament (_), the number of strata contained therein, and the consentration of carbon in each stratum. It is, of course, preferable that the strata be well-defined and continucus.
However, it is emphasized that the drawings are schematic and that the individual strata are not, and need not be perfectly defined.
Each non-conducting stratum (13) of polymeric material comprising the unitary filament ~11) of the present invention is composed of the same polymeric material which comprises the matrix of the electrically-conducting strata (12).
An explication and example of a pxeferred method of forming the union of strata which is the integral ! filamentary structure (11) of the present invention is now set forth.
To prepare integral, electrically-conductive fila-~- ments according to the present invention, one may use a number of special techniques, the most advantageous of which comprehends a modification of the well-known technique of spinning a solution of a fiber-forming polymeric material in a solvent. This improvement comprises:
(1) providing a first stream of a solution of the polymeric material;
(2) providing a second stream of the same solu-. . .
tion of the polymeric material, and dispersing in the second stream between about 30 and 70 percent by weight, based upon the weight of the polymeric material, of a ~inely~divided, electrically-conductive carbon black which does not dissolve in, or react with the solvent;
(3~ providing a third stream identical to the first stream;
(~) providing a fourth stream identical to the second stream; and (5) causing the first, second, third, and fourth streams to join in order into a composite stream without appreciable mixing of the individual component streams thereof, and spinning the resulting composite stream into integral filaments.
In a preferred embodiment of this process, the : first and second streams described above are introduced simul-taneously into the inlet end of an interfacial surface generator which generates between 8 and about 2000 total layers and the resulting multi-layered composite stream is spun into integral filaments by standard wet or dry spinning techniques.
In another preferred embodiment of this process, many filaments are extruded in a tow, which is cut into staple and subsequently handled by conventional methods to produce a conductive spun yarn.
BRIEF DESCRIPTION OF THE DRAWTNG
.
For a more complete understanding of the present invention, reference should be made to the detailed description 57~
of the preferred embodiments thereof, which is set fGrth below, which description should be read together with the accompanying drawing, wherein:
FIG. 1 and FIG. 2 are perspective views schematically illustrating embodiments of an inteyral, electrically-con-ductive filament according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The polymeric material comprising the integral, electrically-conductive textile filament of the present invention may be any of the well-known film or fiber-forming polymers commonly employed in the art, such as acrylics, acetates, modacrylics, cellulosics, polystyrenes, polyolefins, polyesters, and polyamides. Acrylonitrile polymers having at least about 85 percent by weight of acrylonitrile and up to about 15 percent by weight of another polymerizable mono-olefinic monomer copolymerizable therewith have been shown to be especially advantageous. The unitary filament must comprise at least two electrically-conducting, longitudinally-directed strata of ~iber-forming polymeric material, each of which has uniformly dispersed therein finely-divided particles of an electrically-conductive carbon black. A particle size of about 20 to 40 m~ is preferred.
The number of electrically-conductive strata and the appropriate concentration of electrically-conductive carbon black in the individual electrically-conductive strata were determined empirically. In this regard, it was desired that the electrical resistance of the unitary filament be not more than about 109 ohms/cm, and for many applications, between about 10- and 109 ohmsjcm. Under the latter conditions, the unitary filament is eminently suitable for employment in a wide variety of fabrics for preventing the accumulation of hiyh charges of static electricity while presenting no appreciable electrocution hazard.
7~
The filament of the present invention accordingly has:
(a) from 2 to about 1000 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material having finely-divided particles of electrically-conductive carbon black uniformly dispersed therein, the concentration of electrically-conductive carbon black in each electrically-conducting stratum being within the following limits:
: 10 (1) For 2 electrically-conducting strata:
: from about 30 percent by weight -- at a total concentration of carbon in the integral filament of about 1/2 percent by weight -- to about 70 percent by weight -- at a total concentra-tion of carbon in the integral filament of about 1/4 percent by weight; and (2) For about 1000 electrically-conducting strata: from about 30 percent by weight -- at a total : concentration of carbon in the integral filament of about ; 12 percent ~y weight -- to about 70 percent by weight --at a total concentration of carbon in the integral filament of about 2 percent by weight; and '~ (b) in coextensive union with each electrically-~ conducting stratum along the length of at least one major : surface therof, a non-conducting stratum of the same ~ 25 fiber-forming pol~meric material.
: Furthermore, the integral, electrically-conductive : textile filament of the present invention is particularly useful when there are 4 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material, each having finely-di~ided particles of electrically-conductive carbon black uniformly dispersed therein in a concentration of ~0 - 60 percent by weight, the total concentration of carbon in the integral filament being between 4 and 6 percPnt by wei~ht.
7(~
Referring to ~he drawing, although t~lo longitudinally-directed electrically-conducting strata (12) are sufficient to afford the combination of properties long sought after (see FIG. 1), a larger number of electrically-conducting strata (12) has been found particularly advantageous. (See FIG. 2, wherein the preferred embodiment comprising 4 electrically-conducting strata (12) is shown.) Each electrically-conducting stratum (12) is joined in a coextensive union along the length of at least one of its major surfaces with a non-conducting stratum (13) of the same polymeric material to form an integral or unitary filamentary structure ~11). As the component strata of this structure cannot be individually separated or removed from the unit, the integral structure (11) of the present invention is decidedly different from those composite structures of the prior art which, comprising distinct layers or plies joined by adhesive and/or the application of heat and pressure, are subject to delamination and/or des~uamation, which in turn results in loss of conductivity of the structure.
Moreover, the electrically-conducting strata (12) of the unitary structure (11) of the present invention are manifestly unlike the prior art's long, slender particles of dispersed conductive block copolymeric material, which are difficultly fashioned in reproducible form from a narrow choice of conductive polymeric materials. In contradist~nction to these prior art structures, the electrically-conducting strata (12) of the unitary filament (11) of the present invention comprise finely divided particles of electrically-conductive carbon black -- e.g., roughly spherical particles of electrically-conductive carbon black having an average diameter of between about 20 and 40 m~ -- uniformly dispersed in a non-conducting polymeric matrix. Moreover, the desired electrical co~ductivity of a variety of polymeric filaments is readily and economically achieved, and easily reproduced.
;5~
The height of each electrically-conducting stratum (12) is not critical. It varies with the diameter of the filament (_), the number of strata contained therein, and the consentration of carbon in each stratum. It is, of course, preferable that the strata be well-defined and continucus.
However, it is emphasized that the drawings are schematic and that the individual strata are not, and need not be perfectly defined.
Each non-conducting stratum (13) of polymeric material comprising the unitary filament ~11) of the present invention is composed of the same polymeric material which comprises the matrix of the electrically-conducting strata (12).
An explication and example of a pxeferred method of forming the union of strata which is the integral ! filamentary structure (11) of the present invention is now set forth.
To prepare integral, electrically-conductive fila-~- ments according to the present invention, one may use a number of special techniques, the most advantageous of which comprehends a modification of the well-known technique of spinning a solution of a fiber-forming polymeric material in a solvent. This improvement comprises:
(1) providing a first stream of a solution of the polymeric material;
(2) providing a second stream of the same solu-. . .
tion of the polymeric material, and dispersing in the second stream between about 30 and 70 percent by weight, based upon the weight of the polymeric material, of a ~inely~divided, electrically-conductive carbon black which does not dissolve in, or react with the solvent;
(3~ providing a third stream identical to the first stream;
(4) providing a fourth stream identical to the second stream; and ~Q657~
(5) causing the first, second, third, and fourth streams to join in order into a composite stream withou~
appreciable mixing of the individual component streams thereo, and spinning the resulting composite stream into integral fila-ments. The polymeric material is any of the well-known film or fiber-forming polymers commonly employed in the art, examples thereof being set forth above, and the solution thereof is prepared by dissolving the chosen polymeric material in a liquid which is a good solvent therefor, but which does not react with or dissolve the finely-divided electrically-conductive carbon black which is to be dispersed in the second stream by standard techniques. The individual streams are first de-gassed, after which they are joined by introducing them simultaneously in parallel relationship into a cylindrical member which terminates in an orifice or jet. If the "wet spinnlng" technique has been chosen, the composite stream ls "spun" or extruded through the jet into a coagulating bath, which containC a liquid which is miscible with the polymer solvent, but is itself a non-solvent for the polymer and causes the polymer to precipitate. The filament so produced is then washed, generally countercurrently with water, to remove the spinning solvent, and is then dried and finally wound on a package for subse-quent utilization in the production of a wide variety of antistatic fabrics. If the "dry spinning" technique has been chosen, the solvent contained in the composite stream must be volatile, and the composite stream is "spun" or extruded through the jet into the air or an inert gas atmosphere, whereupon a filament is formed by evaporation of solvent from the composite stream. Dry spinning is usually effected in the art employing the cylindrical member in a vertical position. Moreover, the cylindrical member is generally jacketed for temperature control, and outfitted so that the air, steam, or inert gas may be passed over the je~
;5~
either concurrently or countercurrently as required. Down-ward spinning is preferred for low-denier fibers and upward spinning for high deniers, for better control of draw by eliminating the influence of gravity.
Found to be of particular significance and advantage in the practice of this process is the step of introducing the first and second streams referred to above simultaneously into the inlet end of an interfacial surface generator and then passing the resulting multi-layered composite stream , through the jet and into a coagulating bath or into the air .~ or an inert gas atmosphere. Interfacial surface generators such as those specified in U. S. patents 3,404,869 and 3,583,678 have been employed with beneficial results.
In a preferred embodiment, particularly good re-; 15 sults are obtained in the preparation of filaments according to present invention when the fiber-forming polyrneric material is a long-chain synthetic polymer composed of at least about ~ 85~ by weight of acrylonitrile units with the remainder : being one or more other mono-olefinic monomers copolymeriz-. , able therewith, such as: vinyl acetate; alkyl esters of ~: acrylic and methacrylic acid; vinyl bromide; as well as monomers having an affinity for acid dyestuffs, particularly those containing a tertiary or quarternary nitrogen in the molecule, such as vinyl pyridine or methyl vinyl pyridine;
and monomers having an affinity for basic dyestuffs, particularly those containing a sulfonic or carboxylic acid group, such as alkyl sul~onic acid, itaconic acid, among many others. The electrically-conductive material employed in this preferred embodiment is an electrically-conductive carbon black having a particle size between about 20 and 40 m~. The acrylonitrile polymer is dissolved in an inorganic solvent as specified in U. S. Patents 2,558,730 and 2,916,348 or in an or~anic ;57~
solvent as shown in Knudsen, Textile Research Journal 33, 13-20 (1963). The first and second streams are introduced into the inlet end of an interfacial surface generator as specified in U. S. Patent 3,583,678 to produce a composite stream of between 8 and about 2 thousand total layers, which composite stream is then spun through a jet into a coagulating bath, wherein the polymer is precipitated, and the unitary ; filament so produced is washed countercurrently with water, stretched, crimped and dried.
The present invention may be better understood by a reference to the following illustrative examples, wherein all parts and percentages are by weight unless otherwise indicatedO
Example 1.
This example specifies detail concerning a preferred method of making an integral, electrically-con-ductive filament according to the present invention, and sets forth some of the basic properties of the fila-ment.
An acrylonitrile homopolymer, the preparation of which is exemplified by U. S. Patent No. 2,~47,405, was dissolved in a 60 percent solution of zinc chloride to produce a stock solution containing about 11 percent of the acrylic polymer. A first stream of this solution was provided in a conduit. To a portion of the stock solution which was used to provide the first stream was added a commercially-available electrically-conductive carbon black having an average particle diameter of 30 m~, in an amount sufficient to provide a dispersion having the foliowing composition: ~% acrylonitrile homopolymer,
appreciable mixing of the individual component streams thereo, and spinning the resulting composite stream into integral fila-ments. The polymeric material is any of the well-known film or fiber-forming polymers commonly employed in the art, examples thereof being set forth above, and the solution thereof is prepared by dissolving the chosen polymeric material in a liquid which is a good solvent therefor, but which does not react with or dissolve the finely-divided electrically-conductive carbon black which is to be dispersed in the second stream by standard techniques. The individual streams are first de-gassed, after which they are joined by introducing them simultaneously in parallel relationship into a cylindrical member which terminates in an orifice or jet. If the "wet spinnlng" technique has been chosen, the composite stream ls "spun" or extruded through the jet into a coagulating bath, which containC a liquid which is miscible with the polymer solvent, but is itself a non-solvent for the polymer and causes the polymer to precipitate. The filament so produced is then washed, generally countercurrently with water, to remove the spinning solvent, and is then dried and finally wound on a package for subse-quent utilization in the production of a wide variety of antistatic fabrics. If the "dry spinning" technique has been chosen, the solvent contained in the composite stream must be volatile, and the composite stream is "spun" or extruded through the jet into the air or an inert gas atmosphere, whereupon a filament is formed by evaporation of solvent from the composite stream. Dry spinning is usually effected in the art employing the cylindrical member in a vertical position. Moreover, the cylindrical member is generally jacketed for temperature control, and outfitted so that the air, steam, or inert gas may be passed over the je~
;5~
either concurrently or countercurrently as required. Down-ward spinning is preferred for low-denier fibers and upward spinning for high deniers, for better control of draw by eliminating the influence of gravity.
Found to be of particular significance and advantage in the practice of this process is the step of introducing the first and second streams referred to above simultaneously into the inlet end of an interfacial surface generator and then passing the resulting multi-layered composite stream , through the jet and into a coagulating bath or into the air .~ or an inert gas atmosphere. Interfacial surface generators such as those specified in U. S. patents 3,404,869 and 3,583,678 have been employed with beneficial results.
In a preferred embodiment, particularly good re-; 15 sults are obtained in the preparation of filaments according to present invention when the fiber-forming polyrneric material is a long-chain synthetic polymer composed of at least about ~ 85~ by weight of acrylonitrile units with the remainder : being one or more other mono-olefinic monomers copolymeriz-. , able therewith, such as: vinyl acetate; alkyl esters of ~: acrylic and methacrylic acid; vinyl bromide; as well as monomers having an affinity for acid dyestuffs, particularly those containing a tertiary or quarternary nitrogen in the molecule, such as vinyl pyridine or methyl vinyl pyridine;
and monomers having an affinity for basic dyestuffs, particularly those containing a sulfonic or carboxylic acid group, such as alkyl sul~onic acid, itaconic acid, among many others. The electrically-conductive material employed in this preferred embodiment is an electrically-conductive carbon black having a particle size between about 20 and 40 m~. The acrylonitrile polymer is dissolved in an inorganic solvent as specified in U. S. Patents 2,558,730 and 2,916,348 or in an or~anic ;57~
solvent as shown in Knudsen, Textile Research Journal 33, 13-20 (1963). The first and second streams are introduced into the inlet end of an interfacial surface generator as specified in U. S. Patent 3,583,678 to produce a composite stream of between 8 and about 2 thousand total layers, which composite stream is then spun through a jet into a coagulating bath, wherein the polymer is precipitated, and the unitary ; filament so produced is washed countercurrently with water, stretched, crimped and dried.
The present invention may be better understood by a reference to the following illustrative examples, wherein all parts and percentages are by weight unless otherwise indicatedO
Example 1.
This example specifies detail concerning a preferred method of making an integral, electrically-con-ductive filament according to the present invention, and sets forth some of the basic properties of the fila-ment.
An acrylonitrile homopolymer, the preparation of which is exemplified by U. S. Patent No. 2,~47,405, was dissolved in a 60 percent solution of zinc chloride to produce a stock solution containing about 11 percent of the acrylic polymer. A first stream of this solution was provided in a conduit. To a portion of the stock solution which was used to provide the first stream was added a commercially-available electrically-conductive carbon black having an average particle diameter of 30 m~, in an amount sufficient to provide a dispersion having the foliowing composition: ~% acrylonitrile homopolymer,
6% carbon black. A second stream was provided from this dispersion. Through the utilization of 2 metering ~Q~i5~
pumps, the first and second streams were introduced simul-taneously into the inlet end of an interfacial surface generator in the following proportion: 90 percent first stream and lO percent second stream. The interfacial surface generator, which is pictured and specified in U. S.
Patent No. 3,583,678, comprised 1 individual interfacial surface generating element having 4 passageways therethrough.
Accordingly, the total number of layers generated was 8 (4 conducting and ~ non-conducting). The resulting composite , stream was spun through a jet into a coagulating bath of 4~ percent zinc chloride in water, and the unitary filamentary structure so produced was washed countercurrently with water, elongated to approximately 9 times its original length, and dried in air. The filament was finally wound on a spool for subsequent utilization in the production of an antistatic fabric.
The filament had a denier of 15 and a total carbon black concentration of 5%. Using a Keithley 610C Electrometer, - the electrical resistance of the filament was determined to be 10 ohms/cm. This filament, which is hereinafter designated Filament A, is compared with an acrylonitrile homopolymer filament of 15 denier, which is designated Filament B, which has an electxical resistance of 10l4 ohms/cm. See Table I.
Suc~ a comparison reveals that the desirable textile properties o~ acrylic homopolymer filaments are retained by Filament A
while significant conductivity is achieved.
Example 2.
~ number of procedures otherwise identical to that of Example 1 were carried out, except that the number of electrically-conductive strata and the composition of each electrically-conductive stratum in the integral filament were varied as set forth in Table I on the following page.
Filaments C-E and others described below were prepared and 5~
their physical properties were determined. The results of these determinations are also found in Table I. ~, TABLE I
No of [C] in Total Electri- Each Elec- [C] in cally - trically - the Inte- Resis-Conductive Conductive gral trance Extension Tenacity, FilamentLayers Layer Filament - ohm/cm % g/den.
A 4 50% 5% 107 13.a 3.9 . (This : Invention) ; B 0 0 0 1014 10.0 4.0 (For : Comparison) C 64 60% 10% 105 l4.6 3.3 (This Invention) D 1000 50% 2% 10 15.1 4.2 (This Invention) E 1000 50~ 5% 10 14.1 3.2 (This Invention) For more than about lOOO electrically-conductive layers, the resistance of the filament exceeded lO9 ohms/
cm. For but one conductive layer, the filament fibrillated undesirably.
Example 3.
This example is illustrative of the utilit,y and durability of an integral, electrically-conductive filament according to the present invention.
EXPERIMENT A
Filament A from Example l above was cut into staple lengths of 3 inches and blended by standard techniques with a 16-denier nylon 6 staple product having a staple ~6~
length of 6 inches to produce a blend contai~ing 2 percent of Filament A. This blend was processed by standard techniques into a 2.25/2 cotton count yarn having 3.5 Z
turns and 2.5 S turns per inch. This yarn is designated Yarn A. Employing a jute backing material and utilizing a standard tufting machine, a 30 oz/yd2 level loop carpet (hereinafter designated Carpet A) was prepared from Yarn A.
EXPERIMENT B
Carpet A was then subjected to the Static Electricity Test set forth below. The results of such testing are re-ported in Table II below as "Initial Static Electricity."
Following the initial static electricity testing, ... .
Carpet A was then subjected to an accelerated wearing procedure for 60 hours, after which, testing of static electricity was again effected. The results of such testing are reported in Table II below as "Final Static Electricity."
From Table II it can be seen that carpet A was not only initially static protected (viz., it did not allow the generation of a static charge in excess of 3000 volts, which is generally accepted as the average threshhold level of human sensitivity), but carpet A was also static protected after extensive wear. Moreover, microscopic examination of the electrically-conductive filament A revealed substantially no deterioration thereof.
Static Electricity Test:
The fabric to be tested is first cut into sample squares 36 inches on a side. These samples are conditioned for 7 days by being hung from racks in a test room equipped with a rubber 100r mat and having an area of at least 100 square feet, wherein the temperature is controlled at 70+
2F and the relative humidity is controlled at 20%+ 1~.
~Q~
Free circulation of air over all sample surfaces is effected, but the samples are not allowed to contact each other. A
pair of Neolite or PVC-sole test shoes is also conditioned for the same period, under the same conditions.
Residual static charge on the rubber floor mat is then neutralized by passing twice over its entire surface a polonium wand, which consists of 6 polonium 210 alloy strips mounted end-to-end on a head attached to a handle.
A fabric sample is then placed upon the xubber floor mat, and its residual static charge is neutralized in the same m~nnex. The soles of the test shoes are then cleaned by sanding their entire surface with fine sandpaper, followed by a wiping with cheesecloth to remove dust particles.
Wearing the test shoes and holding a hand probe which is connected to an electrostatic detection head, a human operator steps upon the carpet sample and grounds the probe. Then while holding the hand probe, the operator walks normally on the sample at a rate of 2 steps a ~econd for a 30-second period, being careful not to scuff or rub the shoes over the fabric. If at the end of the 30-second period the voltage has not xeached a steady maximum, the walk is continued for an additional 30 seconds. The maximum voltage recoxded during the walk is the static level of the sample, the average for two sperators being recorded in Table II as static electricity in volts.
~17~
i7g Table II
Initial Static Final Static Electricity, VoltsElectricity, Volts ~13 1~) Carp~tNeolite Neolite Sample SolesPVC Soles SolesPVC Soles A (T~is 1400 1200 1500 1~00 Invention) .- - ,f f ~,, c -Pile fabrics such as carpet A, the prepatation of which is described above, when employed in an atmosphere having a relative humidity of at least 20% will not generate a static charge above about 3000 volts, which is in prox-imlty to the threshold level of human sensitivity. Under the same conditions, a standard nylon 6 carpet can generate up to about 14,000 volts. Pile fabrics such as carpet A, moreover, when containing an integral, electrically-conduc-tive filament having an electrical resistance between about 104 and 109 ohmsjcm, do not present an electrocution hazard to those contacting them in the event of an accidental and simultaneous contact of such fabrics with a source of essen-tially unlimited electrical current, as is available from an ordinary electrical outlet, or an electrical appliance short-circuited by insulation failure.
The unique combination of properties possessed by the integral, electrically-conductive filament according to the present invention renders it especially suitable as a continuous filament or a staple product for use not only in carpets, rugs, and other floor coverings, but also in bed coverings, especially in hospitals; in curtains, especially in hospitals for separation of cubicles; in articles of apparel, especially uniforms and undergarments such as slips; in hosiery, especially in panty hose and half hose;
in heater fabrics; and as sewing threads.
Although the present invention has been described in detail with respect to certain preferred embodiments thereof, it is apparent to those of skill in the art that variation~ and modifications in this detail may be effected without any departure ~rom the spirit and scope of the present invention, as defined in the hereto-appended claims.
pumps, the first and second streams were introduced simul-taneously into the inlet end of an interfacial surface generator in the following proportion: 90 percent first stream and lO percent second stream. The interfacial surface generator, which is pictured and specified in U. S.
Patent No. 3,583,678, comprised 1 individual interfacial surface generating element having 4 passageways therethrough.
Accordingly, the total number of layers generated was 8 (4 conducting and ~ non-conducting). The resulting composite , stream was spun through a jet into a coagulating bath of 4~ percent zinc chloride in water, and the unitary filamentary structure so produced was washed countercurrently with water, elongated to approximately 9 times its original length, and dried in air. The filament was finally wound on a spool for subsequent utilization in the production of an antistatic fabric.
The filament had a denier of 15 and a total carbon black concentration of 5%. Using a Keithley 610C Electrometer, - the electrical resistance of the filament was determined to be 10 ohms/cm. This filament, which is hereinafter designated Filament A, is compared with an acrylonitrile homopolymer filament of 15 denier, which is designated Filament B, which has an electxical resistance of 10l4 ohms/cm. See Table I.
Suc~ a comparison reveals that the desirable textile properties o~ acrylic homopolymer filaments are retained by Filament A
while significant conductivity is achieved.
Example 2.
~ number of procedures otherwise identical to that of Example 1 were carried out, except that the number of electrically-conductive strata and the composition of each electrically-conductive stratum in the integral filament were varied as set forth in Table I on the following page.
Filaments C-E and others described below were prepared and 5~
their physical properties were determined. The results of these determinations are also found in Table I. ~, TABLE I
No of [C] in Total Electri- Each Elec- [C] in cally - trically - the Inte- Resis-Conductive Conductive gral trance Extension Tenacity, FilamentLayers Layer Filament - ohm/cm % g/den.
A 4 50% 5% 107 13.a 3.9 . (This : Invention) ; B 0 0 0 1014 10.0 4.0 (For : Comparison) C 64 60% 10% 105 l4.6 3.3 (This Invention) D 1000 50% 2% 10 15.1 4.2 (This Invention) E 1000 50~ 5% 10 14.1 3.2 (This Invention) For more than about lOOO electrically-conductive layers, the resistance of the filament exceeded lO9 ohms/
cm. For but one conductive layer, the filament fibrillated undesirably.
Example 3.
This example is illustrative of the utilit,y and durability of an integral, electrically-conductive filament according to the present invention.
EXPERIMENT A
Filament A from Example l above was cut into staple lengths of 3 inches and blended by standard techniques with a 16-denier nylon 6 staple product having a staple ~6~
length of 6 inches to produce a blend contai~ing 2 percent of Filament A. This blend was processed by standard techniques into a 2.25/2 cotton count yarn having 3.5 Z
turns and 2.5 S turns per inch. This yarn is designated Yarn A. Employing a jute backing material and utilizing a standard tufting machine, a 30 oz/yd2 level loop carpet (hereinafter designated Carpet A) was prepared from Yarn A.
EXPERIMENT B
Carpet A was then subjected to the Static Electricity Test set forth below. The results of such testing are re-ported in Table II below as "Initial Static Electricity."
Following the initial static electricity testing, ... .
Carpet A was then subjected to an accelerated wearing procedure for 60 hours, after which, testing of static electricity was again effected. The results of such testing are reported in Table II below as "Final Static Electricity."
From Table II it can be seen that carpet A was not only initially static protected (viz., it did not allow the generation of a static charge in excess of 3000 volts, which is generally accepted as the average threshhold level of human sensitivity), but carpet A was also static protected after extensive wear. Moreover, microscopic examination of the electrically-conductive filament A revealed substantially no deterioration thereof.
Static Electricity Test:
The fabric to be tested is first cut into sample squares 36 inches on a side. These samples are conditioned for 7 days by being hung from racks in a test room equipped with a rubber 100r mat and having an area of at least 100 square feet, wherein the temperature is controlled at 70+
2F and the relative humidity is controlled at 20%+ 1~.
~Q~
Free circulation of air over all sample surfaces is effected, but the samples are not allowed to contact each other. A
pair of Neolite or PVC-sole test shoes is also conditioned for the same period, under the same conditions.
Residual static charge on the rubber floor mat is then neutralized by passing twice over its entire surface a polonium wand, which consists of 6 polonium 210 alloy strips mounted end-to-end on a head attached to a handle.
A fabric sample is then placed upon the xubber floor mat, and its residual static charge is neutralized in the same m~nnex. The soles of the test shoes are then cleaned by sanding their entire surface with fine sandpaper, followed by a wiping with cheesecloth to remove dust particles.
Wearing the test shoes and holding a hand probe which is connected to an electrostatic detection head, a human operator steps upon the carpet sample and grounds the probe. Then while holding the hand probe, the operator walks normally on the sample at a rate of 2 steps a ~econd for a 30-second period, being careful not to scuff or rub the shoes over the fabric. If at the end of the 30-second period the voltage has not xeached a steady maximum, the walk is continued for an additional 30 seconds. The maximum voltage recoxded during the walk is the static level of the sample, the average for two sperators being recorded in Table II as static electricity in volts.
~17~
i7g Table II
Initial Static Final Static Electricity, VoltsElectricity, Volts ~13 1~) Carp~tNeolite Neolite Sample SolesPVC Soles SolesPVC Soles A (T~is 1400 1200 1500 1~00 Invention) .- - ,f f ~,, c -Pile fabrics such as carpet A, the prepatation of which is described above, when employed in an atmosphere having a relative humidity of at least 20% will not generate a static charge above about 3000 volts, which is in prox-imlty to the threshold level of human sensitivity. Under the same conditions, a standard nylon 6 carpet can generate up to about 14,000 volts. Pile fabrics such as carpet A, moreover, when containing an integral, electrically-conduc-tive filament having an electrical resistance between about 104 and 109 ohmsjcm, do not present an electrocution hazard to those contacting them in the event of an accidental and simultaneous contact of such fabrics with a source of essen-tially unlimited electrical current, as is available from an ordinary electrical outlet, or an electrical appliance short-circuited by insulation failure.
The unique combination of properties possessed by the integral, electrically-conductive filament according to the present invention renders it especially suitable as a continuous filament or a staple product for use not only in carpets, rugs, and other floor coverings, but also in bed coverings, especially in hospitals; in curtains, especially in hospitals for separation of cubicles; in articles of apparel, especially uniforms and undergarments such as slips; in hosiery, especially in panty hose and half hose;
in heater fabrics; and as sewing threads.
Although the present invention has been described in detail with respect to certain preferred embodiments thereof, it is apparent to those of skill in the art that variation~ and modifications in this detail may be effected without any departure ~rom the spirit and scope of the present invention, as defined in the hereto-appended claims.
Claims (3)
1. An integral, electrically-conductive textile filament having a resistance of not more than about 109 ohms/cm, the filament comprising:
(a) from 2 to about 1000 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material having finely-divided particles of electrically-conductive carbon black uniformly dispersed therein, the concentration of electrically-conductive carbon black in each electrically-conducting stratum being within the following limits:
(1) For 2 electrically-conducting strata:
from about 30 percent by weight -- at a total concentration of carbon in the integral filament of about 1/2 percent by weight -- to about 70 percent by weight -- at a total concentration of carbon in the integral filament of about 1/4 percent by weight; and (2) For about 1000 electrically-conducting strata: from about 30 percent by weight -- at a total concentration of carbon in the integral filament of about 12 percent by weight -- to about 70 percent by weight --at a total concentration of carbon in the integral filament of about 2 percent by weight; and (b) in coextensive union with each electrically-conducting stratum along the length of at least one major surface thereof, a non-conducting stratum of the same fiber-forming polymeric material.
(a) from 2 to about 1000 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material having finely-divided particles of electrically-conductive carbon black uniformly dispersed therein, the concentration of electrically-conductive carbon black in each electrically-conducting stratum being within the following limits:
(1) For 2 electrically-conducting strata:
from about 30 percent by weight -- at a total concentration of carbon in the integral filament of about 1/2 percent by weight -- to about 70 percent by weight -- at a total concentration of carbon in the integral filament of about 1/4 percent by weight; and (2) For about 1000 electrically-conducting strata: from about 30 percent by weight -- at a total concentration of carbon in the integral filament of about 12 percent by weight -- to about 70 percent by weight --at a total concentration of carbon in the integral filament of about 2 percent by weight; and (b) in coextensive union with each electrically-conducting stratum along the length of at least one major surface thereof, a non-conducting stratum of the same fiber-forming polymeric material.
2. The integral, electrically-conductive textile filament of claim 1, wherein the polymeric material is an acrylonitrile polymer having at least about 85 percent by weight of acrylonitrile and up to about 15 percent by weight of another polymerizable mono-olefinic monomer copolymerizable therewith.
3. The integral, electrically-conductive textile -filament of claim 2, wherein there are 4 electrically-conducting, longitudinally-directed strata of fiber-forming polymeric material, each having finely-divided particles of electrically-conductive carbon black uniformly dispersed therein in a concentration of 40 - 60 percent by weight, the total concentration of carbon in the integral filament being between 4 and 6 percent by weight.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/681,680 US4045949A (en) | 1976-01-02 | 1976-04-29 | Integral, electrically-conductive textile filament |
| US681,680 | 1991-04-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1096570A true CA1096570A (en) | 1981-03-03 |
Family
ID=24736297
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA277,204A Expired CA1096570A (en) | 1976-04-29 | 1977-04-28 | Integral, electrically-conductive textile filament |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS52152513A (en) |
| BE (1) | BE854105A (en) |
| CA (1) | CA1096570A (en) |
| CH (1) | CH625570A5 (en) |
| DE (1) | DE2718343C2 (en) |
| ES (1) | ES458175A1 (en) |
| FR (1) | FR2361485A1 (en) |
| IN (1) | IN146424B (en) |
| IT (1) | IT1104571B (en) |
| LU (1) | LU77218A1 (en) |
| MX (1) | MX145086A (en) |
| NL (1) | NL7704725A (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5430919A (en) * | 1977-08-08 | 1979-03-07 | Kanebo Ltd | Electrically conductive conjugate fiber |
| DE2850713C2 (en) * | 1978-11-23 | 1986-10-09 | Akzo Gmbh, 5600 Wuppertal | Antistatic thread structure |
| DE2908376C2 (en) * | 1979-03-03 | 1985-09-26 | Akzo Gmbh, 5600 Wuppertal | Process for making an antistatic carpet fiber |
| JPS564713A (en) * | 1979-06-25 | 1981-01-19 | Japan Exlan Co Ltd | Production of homogeneous dispersion of carbon black and production of spinning dope for organic antistatic fiber containing the same |
| JPH03137212A (en) * | 1989-10-24 | 1991-06-11 | Kanebo Ltd | Raw fiber for cleaning brush |
| DE9108057U1 (en) * | 1991-07-01 | 1991-08-22 | August Mink KG, 7320 Göppingen | Technical brush with roller or strip-shaped brush body and, depending on the respective application, a wide variety of bristles |
| JPH0594284U (en) * | 1992-05-11 | 1993-12-24 | 鐘紡株式会社 | Sewing thread containing conductive filament |
| DE10228603B4 (en) * | 2002-06-26 | 2006-07-20 | Klaus Bloch | Hybridmonofilament |
| JP2007119931A (en) | 2005-10-25 | 2007-05-17 | Bussan Nanotech Research Institute Inc | Synthetic fiber |
| DE102007009118A1 (en) * | 2007-02-24 | 2008-08-28 | Teijin Monofilament Germany Gmbh | Electrically conductive threads, fabrics produced therefrom and their use |
| DE102007009119A1 (en) * | 2007-02-24 | 2008-08-28 | Teijin Monofilament Germany Gmbh | Electrically conductive threads, fabrics produced therefrom and their use |
| DE102007009117A1 (en) * | 2007-02-24 | 2008-08-28 | Teijin Monofilament Germany Gmbh | Electrically conductive threads, fabrics produced therefrom and their use |
| CN110945167A (en) | 2017-09-28 | 2020-03-31 | 东丽株式会社 | Conductive composite fiber |
Family Cites Families (26)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2129594A (en) * | 1937-11-08 | 1938-09-06 | Shimamoto Takejiro | Animal trap |
| US2428046A (en) * | 1943-08-03 | 1947-09-30 | Wayne A Sisson | Artificial filaments |
| US2714569A (en) * | 1952-01-18 | 1955-08-02 | Dobeckmun Co | Laminated thread |
| US3329557A (en) * | 1955-04-06 | 1967-07-04 | Du Pont | Static resistant filament and process therefor |
| US2847405A (en) * | 1957-01-10 | 1958-08-12 | American Cyanamid Co | Continuous process for the polymerization of acrylonitrile |
| US3069746A (en) * | 1957-05-20 | 1962-12-25 | Metal Film Company Inc | Laminated textile threads |
| US3288175A (en) * | 1964-10-22 | 1966-11-29 | Stevens & Co Inc J P | Textile material |
| US3531368A (en) * | 1966-01-07 | 1970-09-29 | Toray Industries | Synthetic filaments and the like |
| US3582444A (en) * | 1967-05-01 | 1971-06-01 | Dow Chemical Co | Self-extinguishing and static charge resistant pile fabric |
| JPS4810380B1 (en) * | 1967-07-27 | 1973-04-03 | ||
| NO126383B (en) * | 1967-11-18 | 1973-01-29 | Teijin Ltd | |
| US3586597A (en) * | 1967-11-20 | 1971-06-22 | Teijin Ltd | Cloth having durable antistatic properties for use in garments and underwear |
| US3590570A (en) * | 1968-03-14 | 1971-07-06 | Teijin Ltd | Sewing thread |
| US3582448A (en) * | 1968-04-23 | 1971-06-01 | Teijin Ltd | Garments having durable antistatic properties |
| DE1769762A1 (en) * | 1968-07-09 | 1971-08-19 | Basf Ag | Process for the production of polyacrylonitrile threads |
| US3700545A (en) * | 1968-11-13 | 1972-10-24 | Kanegafuchi Spinning Co Ltd | Novel synthetic multi-segmented fibers |
| US3583448A (en) * | 1969-07-16 | 1971-06-08 | Bespack Ind Ltd | Valve stem |
| US3729449A (en) * | 1969-08-27 | 1973-04-24 | Kanegafuchi Spinning Co Ltd | Polyamide fibers composed of the polyamide and methods for producing thereof |
| US3583678A (en) * | 1969-09-15 | 1971-06-08 | Dow Badische Co | Interfacial surface generators |
| IE35809B1 (en) * | 1970-11-27 | 1976-05-26 | Dow Badische Co | Laminate filament and fabric prepared therefrom |
| BE790254A (en) * | 1971-10-18 | 1973-04-18 | Ici Ltd | CONDUCTIVE TEXTILE MATERIALS |
| CA995071A (en) * | 1972-07-14 | 1976-08-17 | Dow Badische Company | Electrically-conductive textile fiber |
| US3803453A (en) * | 1972-07-21 | 1974-04-09 | Du Pont | Synthetic filament having antistatic properties |
| US4035441A (en) * | 1973-06-26 | 1977-07-12 | Toray Industries, Inc. | Polyester filament having excellent antistatic properties and process for preparing the same |
| JPS5812374B2 (en) * | 1975-03-05 | 1983-03-08 | 三菱レイヨン株式会社 | Polyamide chemistries |
| JPS52103525A (en) * | 1976-02-24 | 1977-08-30 | Toray Ind Inc | Antistatic polyacrylonitrile fiber with no humidity dependency |
-
1977
- 1977-04-13 IN IN568/CAL/77A patent/IN146424B/en unknown
- 1977-04-25 DE DE2718343A patent/DE2718343C2/en not_active Expired
- 1977-04-25 JP JP4777177A patent/JPS52152513A/en active Granted
- 1977-04-26 ES ES458175A patent/ES458175A1/en not_active Expired
- 1977-04-27 IT IT22901/77A patent/IT1104571B/en active
- 1977-04-28 CA CA277,204A patent/CA1096570A/en not_active Expired
- 1977-04-28 FR FR7712891A patent/FR2361485A1/en active Granted
- 1977-04-28 LU LU77218A patent/LU77218A1/xx unknown
- 1977-04-29 BE BE177130A patent/BE854105A/en not_active IP Right Cessation
- 1977-04-29 MX MX168966A patent/MX145086A/en unknown
- 1977-04-29 CH CH538577A patent/CH625570A5/en not_active IP Right Cessation
- 1977-04-29 NL NL7704725A patent/NL7704725A/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| CH625570A5 (en) | 1981-09-30 |
| JPS52152513A (en) | 1977-12-19 |
| ES458175A1 (en) | 1978-11-01 |
| JPS563447B2 (en) | 1981-01-24 |
| DE2718343A1 (en) | 1977-11-17 |
| MX145086A (en) | 1982-01-05 |
| DE2718343C2 (en) | 1986-07-24 |
| FR2361485A1 (en) | 1978-03-10 |
| NL7704725A (en) | 1977-11-01 |
| LU77218A1 (en) | 1977-08-18 |
| IT1104571B (en) | 1985-10-21 |
| IN146424B (en) | 1979-06-02 |
| BE854105A (en) | 1977-08-16 |
| FR2361485B1 (en) | 1982-12-31 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |